| 1. |
- Perez, Cristina, et al.
(författare)
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Evaluation of a QT Adaptation Time Estimator for ECG Exercise Stress Test in Controlled Simulation
- 2023
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Ingår i: Computing in Cardiology, CinC 2023. - 2325-8861 .- 2325-887X. - 9798350382525
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Konferensbidrag (refereegranskat)abstract
- Slowed adaptation of the QT interval to sudden abrupt heart rate (HR) changes has been identified as a marker of ventricular arrhythmic risk. However, abrupt HR changes are difficult to induce in patients. Quantifying the QT adaptation time in gradual HR changes, as observed in ECGs recording during an exercise stress test, has been recently proposed. The time lag between the QT series and an instantaneous memoryless HR-dependent QT series along stress test was computed as QT memory. Here, this method was evaluated in a control scenario using simulated exercise stress test ECG signals presenting different QT adaptation times. The method robustness was studied by contaminating the ECGs with muscular noise (MN) signals with different Signal-to-Noise ratio (SNR) values, either synthetic or extracted from real recordings. We found that delineation of the T-wave end point in the first transformed lead from Periodic Component Analysis offers the best performance for low SNR. Moreover, we confirmed that the estimator provides an unbiased estimate of the QT memory introduced in the simulations for the studied range of SNR values (25 to 50 dB).
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| 2. |
- Cederfeldt, Marie, 1957, et al.
(författare)
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A longitudinal study of cognitive impairments in relation to activities in daily life
- 2009
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Ingår i: AT-FORUM, Äldres vardag, 6-8 maj-2009, Älvsjömässan i Stockholm.
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Konferensbidrag (refereegranskat)abstract
- Objective: To examine whether there were any differences in recovery in performance of personal activities of daily living (P-ADL) in relation to cognitive impairments pre- and poststroke from discharge to 6 and 12 months in elderly persons. Methods: Forty-five elderly persons after stroke were assessed at discharge from the hospital at 6 and at 12 months. A questionnaire was used to evaluate the person´s prestroke cognitive status. P-ADL was assessed with the Barthel Index. The Mini Mental State Examination and neuropsychological tests were used to measure cognitive functions. Results: Persons with cognitive impairments before and after stroke did not improve in P-ADL from the acute phase until 6 and 12 months, while persons with intact cognition pre- and poststroke did. Conclusion: Since cognitive problems pre- and poststroke hinder recovery in P-ADL, it is important to be aware of the connection between cognitive impairment and activity limitations in planning the optimal rehabilitation. Key words: ADL, cognitive dysfunction, elderly, longitudinal, prestroke, stroke
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